The prior art demonstrates a number of props and supports for a ladder mechanism. U.S. Pat. No. 4,598,795 to Larson discloses a boom and prop combination for a ladder to aid in supporting the ladder to a building. The prop is attachable to the rungs of the ladder by means of feet or hooks which are snap-fitted over the rungs of the ladder. A boom is connectable to the rungs of the ladder and is used to support a winch or hoist. A cause for concern in the ladder-hoist attachment of the Larson patent is the snap fit of the supporting prop to the ladder rungs. In that the feet or hooks of the prop are snap-fitted over the rungs of the ladder, a possibility exists for the prop to be dislocated from the ladder, should the ladder or prop be jarred in an upward manner.
U.S. Pat. No. 4,121,692 to Morawski discloses a ladder tray which is boltably attachable to a ladder for supporting a ladder against a building wall.
The prior art demonstrates a number of ladder hoist mechanisms for purposes of hoisting loads to an upward location. Some examples of ladder hoist mechanism are depicted in U.S. Pat. No. 2,459,621 to Cobb and U.S. Pat. No. 2,311,070 to Morando. U.S. Pat. No. 3,115,211 to Ostrander. Jr. discloses a ladder hoist which is powered by an electric motor.
However, none of the above references discloses an economical and easily assembled, secure ladder support which can be used in conjunction with a winch mechanism for lifting heavy loads to a roof top.
Many commercial buildings as well as many residences have flat roofs. A great many of these buildings and residences are three stories high or less so that access is only afforded by means of a conventional ladder or a conventional extension ladder. Roof-access elevators are rare in buildings which are three-stories or less in height. On many commercial buildings, heating and air conditioning units are often placed on a flat roof. These roof-situated units can present a dilemma for service and repairmen when heavy parts or objects need to be brought to the roof.
In FIG. 1, a repairman 2 is climbing a ladder 4 which is propped against a flat-roofed building 6. The repairman in using one hand to carry a large object 8 up the ladder 4 has only one hand to hold on to the ladder 4. Such a prior art method of lifting a large or heavy object to a roof top has many inherent dangers. In that only one hand is used for climbing the ladder 4, as the repairman goes up each rung of the ladder, there are times when the repairman does not have any hands in contact with the ladder at all. Thus, the repairman is totally dependent upon a proper positioning of his feet and torso for balance. Furthermore, in that the repairman is carrying an object with one hand on his one side, such a practice makes it nearly impossible or at least extremely difficult to carry objects weighing more than 100 pounds. The unbalanced nature of carrying an object with one hand up a ladder invites an accident, with an accident becoming more likely the heavier the object carried up the ladder is.
Many objects which are required for repair purposes at the rooftop level are too heavy to carry by hand. For example, many air conditioning compressors weigh as much as 300 pounds or more. When a heavy object is needed to be brought to the rooftop, the repairman will have to call for a crane to assist in placing a desired object on the roof. Being dependent upon a crane is often time-consuming in that much time can be spent waiting for the arrival of a crane and crane operator.
Presently, there are many commercial-use ladders and extension ladders on the market which are made of aluminum or fiberglass and which are provided with tubular rungs which extend from one side of the ladder to the other. Access to the tubular cavities of the rungs is provided on either side of such ladders. In that many ladders available today are fabricated and equipped with tubular rungs, a need is seen for an attachable ladder support, which can be securely fitted into the tubular cavity of a ladder rung, which when used in conjunction with a winch mechanism provides a quick and economical means to lift heavy objects to a rooftop.